Jason J. Mendro is a litigation partner in the Washington, D.C. office of Gibson Dunn and serves as Co‐Chair of the Firm’s national Securities Litigation Practice Group, which is consistently recognized as one of the top securities litigation practices in the country. Jason has extensive experience defending class and derivative action lawsuits at the trial and appellate level. He is ranked as a leading (Band 1) lawyer in Securities Litigation by Chambers USA: America’s Leading Lawyers for Business 2022-2024, and he has earned national recognition, being named “Litigator of the Week” by The American Lawyer, a “Rising Star” by Law360 and Super Lawyers, and a 2024 BTI Client Service All-Star by BTI Consulting.

Jason defends a broad spectrum of commercial litigation. He represents companies and their directors and officers in wide-ranging shareholder disputes, including securities class actions, challenges to mergers and acquisitions, and derivative lawsuits. He advises boards of directors and special litigation committees in addressing shareholder litigation demands. He also defends cryptocurrency litigation, challenges to investment services and products, data breach litigation, and claims under the Racketeer Influenced and Corrupt Organizations Act, the False Claims Act, and the Employee Retirement Income Security Act. Jason authors chapters of two leading litigation treatises.

In addition to defending private claims, Jason regularly represents businesses in litigation with the government. He has defended numerous companies in investigations and lawsuits by the Consumer Financial Protection Bureau, the Securities and Exchange Commission, and large coalitions of state attorneys general. He also has represented leading industry groups in challenging administrative rulemakings.

Jason graduated cum laude from Harvard Law School. He earned a bachelor’s degree from the University of Florida, where he graduated first in his class. Jason also served as a law clerk to the Honorable Gerald B. Tjoflat of the United States Court of Appeals for the Eleventh Circuit.

Jason is admitted to practice law in Washington, D.C., New York, California, and numerous federal courts, including the Supreme Court of the United States and the United States Courts of Appeals for the First, Second, Third, Fourth, Fifth, Seventh, Ninth, Eleventh, and D.C. Circuits.

Representative Shareholder Litigation Matters:

  • Won dismissal of class and derivative actions claiming that a multinational financial services company made false disclosures about a leading investment product.  
  • Won dismissal of a securities class action and parallel derivative litigation claiming that a worldwide hotel operator made false and misleading statements concerning its susceptibility to cyberattacks.
  • Won dismissal of derivative claims asserting that the board of directors of a global science and technology innovator misled its investors about its commitment to diversity and inclusion.
  • Won dismissal of derivative claims alleging that the directors and officers of a major retail company failed to oversee the company’s compliance with consumer protection laws.
  • Won dismissal of a securities class action challenging a biotechnology company’s public statements about the development of its products.
  • Won dismissal of multiple class actions challenging a merger that created the world’s largest hotel company.
  • Won dismissal of underwriters from a securities class action arising out of a disputed stock offering by a real estate finance company.
  • Won dismissal of derivative claims against the directors and officers of a leading government contractor arising from its announcement that it entered into a deferred prosecution agreement with the U.S. Department of Justice.
  • Won dismissal of a derivative action claiming that the board of directors of a major pharmaceutical company improperly awarded executive compensation that did not qualify for certain tax deductions.
  • Won dismissal of a derivative action accusing executives of a technology company of backdating stock options.

Other Representative Matters:

  • Won voluntary dismissal of a leading financial services firm from sweeping, multi-district litigation arising from the unprecedented volatility of “meme stocks” in 2021.
  • Won an injunction facilitating investors’ recovery on defaulted Argentine Bonds in what The Financial Times called “the trial of the century” in sovereign debt restructuring.
  • Secured an influential ruling granting partial dismissal of claims against a global cryptocurrency company and helping to shape the definition of “security.”
  • Successfully challenged a controversial Labor Department regulation that would have redefined the obligations of investment professionals.
  • Won a precedent-setting appellate victory that reversed a multi-million-dollar jury verdict under the False Claims Act.
  • Won dismissal of claims under the Racketeer Influenced and Corrupt Organizations Act against a leading debt collection company.
  • Successfully challenged CFTC regulations with sweeping implications for the global swaps market.
  • Represented a leading government contractor in multidistrict litigation arising from a data breach perpetrated against the U.S. government.

Capabilities

Credentials

Education:
  • Harvard University - 2002 Juris Doctor
  • University of Florida - 1998 Bachelor of Arts
Admissions:
  • California Bar
  • District of Columbia Bar
  • New York Bar
Clerkships:
  • US Court of Appeals, 11th Circuit, Hon. Gerald Bard Tjoflat, 2003 - 2004